Organizing and sorting images is a very difficult task. Many websites enable users to post their own photographs or images and often allow them to tag the images with a description or other metadata. However, the tags are often very general and difficult to search or further categorize. Many users do not take the time to adequately categorize their images, and each user may be inconsistent with their categorization. Because each user may categorize their images in a different manner from other users, grouping and organizing large quantities of images can be impossible.
When all the sources of images is combined, the volume of images that may contain the same content, such as an iconic landmark like the Eiffel Tower, can be staggering. When all of the images are available electronically, sorting and categorizing the images to identify important landmarks and select a representative image for each landmark can be very difficult.